Electrical mercury control for refrigeration pumps



July.3l, 1928. I

' T. C. WHITEHEAD ELECTRICAL MERCURY CONTROL FOR REFRIGERATION PUMPS Filed Oct. 22, 1923 auuentoz 7%07nas CWzteZaad M5 JAM Patented July 31, 1928.

1 UNITED STATES PATENT OFFICE.

THOMAS C. WHITEHEAD, OF DETROIT, MICHIGAN.

ELECTRICAL MERCURY CONTROL FOR REFRIGERATION PUMPS.

Application filed October 22, 1923. Serial No. 670,217.

This invention relates to refrigerating apparatus and refers more particularly to means for controlling the operation of an electric motor usedto drive a pump for supplying a refrigerating medium to a refrigerator.

Anobject of the invention is to provide a simple electric control means in WlllCh mercury is preferably used to close an electric circuit for operating the motor.

Another object is to provide efficient and reliable mechanism that is adapted to be operated by the pressure of gas in the refrigerator for automatically actuatlng the control means.

Another object is to provide simple and practical means for adjusting the control mechanism whereby the operation thereof by the pressure operated mechanism may be varied.

Another object is to provide a control mechanism that is simple in construction and that can be manufactured at a comparatively low cost.

With the above and other. obJects in view the invention consists in certain novel features of construction, combination and arrangement of parts as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings Figure 1 is a diagrammatic view of a refrigerating apparatus embodying my lnvention' Figure 2 is a front elevation of the control mechanism;

Figure 3 is an end view of the mechanism illustrated in Figure 2.

Referring now to the drawing in which like, characters of reference designate corresponding parts throughout the several views, the numeral 1 designates generally a refrigerating apparatus including an electric motor 2 adapted to drive a pump 3 for supplying a refrigerating medium to a refrigerator 4.

For controlling the operation of the motor, I preferably provide an electric switch having a substantially U-shaped glass tube 5 in which a small quant ty of mercury is adapted to flow for connectlng the spaced terminals 6 of a pair of electric conductors 7 leading to the motor. For causing the mercury-to flow from one end of the tube to the other and thereby cause the electric circuit to the motor to be alterprevent injury to the tube, there is a resilient band 11 that surrounds the tube at the'center and that is held by the arms of a yieldable clip 12 which is rigidly secured to the upper end of the arm 8 For automatically operating the switch the lower end of the arm 8 preferably extends into a bifurcated upper end of a lever 13 WlllCll is swingingly mounted atits lower end on a pivot 14 secured to the rear wall of the frame 10 and which is provided at itslower end below the pivot with an angular extensum 15 that is connected to the closed end of a curved flexible tube 1.6 extending from a fitting 17 secured to a side wall 1.8 of the frame 10. The tube 16 has a tendency to straighten out under pressure and: in order that the movement thereof may be controlled automatically by the pressure resultin from the temperature of gas within the re rigerator, a tubular portlon 19 of the fitting 17 extends through the side wall 18 of the frame and is connected to a gas conduit 20 leading to the refrigerator 4. Thus, when the temperature of the gas in the refrigerator rises the tube 16 will have a tendency to straighten out with the result that the bifurcated upper end of the lever 13 will move the lower end of the arm 8 to the right and will cause the tube 5 to be tilted to the left so that the mercury therein will connect the terminals 6 and close the electric circuit to the motor for operating the pump. lVhen the temperature of gas in the refrigerator falls after a suflicient quantity of the refrigerating medium has been supplied by the pump, the correspondingly decreased pressure will permit the tube 16 to contract with the result that the lever 13 will move the lower end of the arm 8 to the left and will cause the tube 5 to be rocked to the rightso that the mercury will be disconnected from the terminals and the circuitto the motor will be broken. v

In order that the operation of the switch maybe varied as desired, I preferably provide a pair of bolts 21 that are threaded into the furcations, 22 of the lever 13 so as to be adjustable toward and away from the opposite sides of the arm 8. Thus, by adjusting the/bolts 21 the movement of the switch arm may be regulated so that the motor will be operated. when the gas in the refrigerator reaches different predetermined temperatures.

While I have shown and described the control mechanism for use in Connection with a motor of the refrigerating apparatus it is clearly apparent that such mechanism may be readily used with other apparatus not mentioned specifically herein and that such changes may be resorted to when desired as fall within the scope of what is claimed.

\Vhat I claim as my invention is:

1. In a device of the character described, the combination of a support, a lever pivotally mounted on said support, one end of the said lever being bifurcated, a flexible tube secured to the other end of the said lever, the said tube constituting a pressure responsive device for actuating the said lever, a sec ond lever pivoted to said support, one end of the said second lever extending between the furcations of the said first mentioned lever, a resilient clip on the other end of the said second lever, a containercarried by said clip, electric terminals within the said container, and a liquid within the said container adapted to electrically connect or disconnect the said terminals upon a predetermined movement of said pressure responsive tube;

2. In a device of the character described, the combination of a support, a lever pivota-lly mounted on said support, one end of the said lever being bifurcated, a pressure responsive tube having one end secured to said lever for actuating the same, a second lever pivotally mounted on the support, the said second lever having one end extending between the furcrat'ions of the first mentioned lever, adjust-able elements carried by the furcations of the first mentioned lever for adjusting the engagement of the said first mentioned lever with the said second mentioned lover, a U-shaped clip carried by the sec- 0nd lever, a container carried by the said clip, terminals within the said container and a fluid within the container adapted to electrically connect or disconnect the said terminals upon movement of the pressure responsive tube to certain predetermined points.

In testimony whereof I afiix my signature.

THOMAS C. l/VHITEHEAD. 

